Repeat apparatus for holding negatives used in lithography



March 11, 1958 F. J. RADENclc v 2,825,975

REPEAT APPARATUS POR HOLDING NEGATIvEs USED 1N LITEOGRAPHY Filed May 28, 195e IN V EN TOR.

United .States Patent REPEAT APPARATUS FOR HOLDNG NEGATIVES USED IN LITHOGRAPHY Frank J. Radencic, Kansas City, Kans.

Application May Z8, 1956, Serial No. 587,541

2 Claims. (Cl. 'S3-184.5)

This invention relates generally to equipment for use in processing photo-sensitive materials. .More particularly, the invention is concerned with providing improved apparatus for use in processing a relatively thin, ilat piece of material having a photo-sensitive surface by the successive impositioniupon different, predeterminedly spaced areas of such surface of identical, photo-impressions of an image created by the passage of light through a single image-forming structure. It will be apparent that the invention is thus particularly adapted for use by photolithographers in making a plurality of spaced, identical photo-impressions upon a chemically treated, photo-sensilive surface of a metallic plate from a single negative.

ln photolithography, it is necessary that a negative whose image is to be photo-impressed upon the photosensitive lithographie plate must be aligned and positioned relative to such plate with great accuracy. Where a plate is to be processed with identical photo-impressions thereon aligned with or otherwise disposed in predetermined relationship, it has heretofore been necessary either to repeat the careful positioning and alignment of a single negative for :each photo-impression to be made or to produce a number of identical negatives suicient for simultaneously making the required photo-impressions with each of such negatives requiring .separate positioning relative to the lithographie plate. Both of such procedures have involved unnecessary time and effort and, therefore3 expense.

Accordingly, .itis the primary object of this invention to provide apparatus by which ,identical photo-impressions may be made upon a piece of photo-sensitive material .by the use of a single negative and with the necessity for making manual measurements in order to align the negative for each impression to be made eliminated.

.lt is another important object of this invention to provide such apparatus which includes a guide panel upon which vthe piece of photo-sensitive material to be processed may be disposed and .initially aligned and secured with care relative .to series of perforations provided in the guide panel, and wherein the negative is carried by an apertured, `frame-like .chase adapted to be superimposed over the material to be processed and provided with holes alignable with different pairs of perforations of the guide panel for holding of the chase relative to the guide panel and material by suitable pin means in any of a plurality of `predetermined positions.

ltfis` another important object of the invention to provide ,such apparatus wherein .the .perforations of the guide panel are uniformly spaced at predetermined intervals and arranged in parallel rows adjacent `opposite extremities ofthe guide panel, whereby to serveameasuring function as well as cooperating with Ithe holes of the chase and the pin means for holding the chase relative `to the guideI panel and the photo-sensitive material being processed.

Another important object of the invention is to provide such apparatus wherein the perforations of the guide forations with the perforations of each pair oliset longitudinally of the rows relative to the perforations of other pairs, and in which holes are provided in the chase for each pair of perforations, whereby the position of the chase relative to the guide panel may be shifted by distances less than the spacing of the perforations in any given row thereof.

Another important object of the invention is to provide such apparatus wherein the chase has a plurality of holes arranged in a straight line for each row of perforations of the guide panel, and wherein the holes of each such plurality thereof are uniformly spaced from each other a distance rtliiferent from lthe spacing of the perforations of `the corresponding row of the latter, whereby the position of vthe chase relative 'to the guide panel may be adjusted in increments less than the spacing between either the perforations of any row thereof or the holes of any plurality thereof.

Another important object of the invention is to provide such apparatus of structural nature such that it will be relatively thin and, accordingly, adapted for use in connection with a vacuum frame such as conventionally employed by photolithographers in holding plates to be processed.

Still other important objects of the invention, including important details of construction, will be made clear or become apparent as the following description of an illustrative embodiment of vthe invention proceeds.

In the accompanying drawing:

Fig. l is a top plan view of one embodiment of `apparatus contemplated by the invention;

Fig. 2 is a cross sectional View taken on vline II-H of Fig. l, the thickness ofthe parts being considerably exaggerated without `regard to scale for clarity of illustration; and

Fig. 3 is an enlarged perspective view of one form of pin means suitable for use with the apparatus of Figs. l and 2.

Referring now particularly to Figs. 1 and 2, the -apparatus will be seen to broadly include a guide panel generally designated 10, a chase generally designated 12, an opaque sheet yof paper or the like generally designated 14, an image-carrying negative generally designated 16, land a pair of pin assemblies generally designated 18 and 20. A piece of photo-sensitive material to be processed is illustrated in place on the guide panel 10 and generally designated by the numeral 22.

The guide panel 10 consists of a preferably relatively thin, rectangular sheet 24 of inflexible material, such as 1A@ in. plastic sheet, although the board l0 could obviously be formed of other materials, for instance, a light metal such as aluminum. As illustrated, the guide panel lll `has an upper end 26, a lower end 28 and a pair of opposed sides Si) and 32. Adjacent the side 30 is a straight, elongated, outermost row generally designated 3d of uniformly spaced perforations 36. An elongated, outermost row 38 of similarly spaced perforations 40 is disposed lin like manner adjacent the opposite si-de 32 of guide panel 10, the rows 34 and 38 being parallel, and' each perforation 36 having a corresponding perforation 40 equally spaced from the upper end 26 of panel 10. In similar fashion, elongated, innermost rows 42 and 46 of uniformly spaced perforations 44 and 48 are arranged in parallel relationship to each other and the rows 34 and `38 with row 42 spaced inwardly from row 34 and row A46 `spaced inwardly from row 38. lt will be noted that the perforations 44 and 48 of rows 42 and 46 respectively are oifset longitudinally of the rows 34 and 3S so as 'to be half-way between adjacent pairs of perforations 36 or 40, as the case may be. As an example, `the ice l perforations 36 of row 34 and the perforations 40 of row panel include a plurality of spaced pairs of such per- Y 38 may be spaced from other perforations of the same rows by a distance of l in.,v and the perforations 44 and 48 may similarly be spaced apart within the rows 42 and 46 respectively by a distance of 1/2 in. With such construction, it will be clear that the longitudinal offset between a perforation 36 with its corresponding perforation 40 and a perforation 44 with its corresponding perforation 48 will be 1A. in.

The rows 34, 38, 42 and 46 of perforations above referred to will be understood as provided for use with a chase 12 movable relative to the guide panel 10 in the direction of either of the ends 26 or 28 of panel 10. Such a chase 12 may, for convenience, be referred to as a vertical chase. It will hereinafter become apparent that a similar chase could be provided for movement in a horizontal direction between the sides 30 and 32 of panel 10, and rows of horizontal perforations generally designated 50 and 52 for the outermost rows thereof and 54 and 56 for the innermost rows thereof would normally be provided in the panel in the same manner as described for the vertical rows 34, 38, 42 and 46. Since the disposition and use of the horizontal rows of perforations 50, 52, 54 and 56 and the operation of a horizontal chase (not shown) -corresponds exactly to their vertical counterparts herein specifically discussed, the nature and operation of the horizontally shiftable mechanism, which may be used alternatively with the vertically shiftable chase 12 will be obvious to those skilled in the art.

'I'he photo-sensitive material 22 could conceivably be ofany suitable nature, including photographic paper or the like, although in the photolithographic field for which the invention is primarily intended, the material will consist of a at, sheet-like plate 58 of metal, normally in rectangular shape, and provided with `a chemically treated surface 60 which is photo-sensitive.

The plate 58 to be processed is disposed in superimposed relationship upon a face 62 of gui-de panel 10 with surface 60 facing away from face 62. By conventional measurement and alignment procedures, the plate 58 is then shifted to a predetermined, desired position relative to the guide panel 10 and particularly the rows 34, 38, 42 and 46 of perforations thereon. If desired, other pin receiving openings (not shown) could be provided in the interior portion of the guide panel 10 to aid in or effect the alignment and positioning of a plate S8 of particular dimensions in a particular orientation upon the guide panel 10. However, due to the variance in sizes of plates 58, the plate 58 will normally be oriented and positioned upon the guide panel 10 by manual measurement. Once so disposed upon the guide panel 10, the plate 58 may be attached or held in such position by any suitable means, there being shown in the drawings a number of pieces of adhesive tape or strip 64, which may be used for such purpose.

The vertical chase 12 is rectangular in configuration and of approximately the same length as the width of the guide panel 10 between sides 30 and 32 thereof, but is of width substantially less than the distance between ends 26 and 28 of guide panel 10 in order to permit adjustment and movement of the chase 12 into a number of different vertical positions relative to the guide panel 10. Chase 12 may be formed of any suitable, relatively thin, inflexible, opaque sheet material. The frame-like chase 12 is provided with a preferably rectangular, central aperture 66 for clearance of light through the negative 16 to the photo-sensitive surface 60 of plate 58 during the photolithographic process, as Will hereinafter be more fully explained.

Chase 12 is also provided with pluralities generally designated 68, 70, 72 and 74 of holes respectively designated 76, 78, 80 and 82. Each of said pluralities of holes 1s arranged in a straight vertically disposed line with all lines being parallel and the lines of pluralities 68 and 72 spaced apart the same distance as rows 34 and 42 of perforations in the guide panel 10 and pluralities 70 and 74 similarly spaced apart the same distance as rows 38 and 46 of perforations in the guide panel 10. The holes 76 of plurality 68 thereof are uniformly spaced, as are the holes 78 of plurality 70 thereof, there being a hole 78 corresponding with and exactly opposite to each hole 76. The spacing between lholes 76 and 78 in the outer plurality 68 and 70 respectively may, for example, be 3/8 in., in order to provide for adjustment of the chase 12 relative to the guide panel 10 in increments of 1A; in., as will hereinafter become more clear. Five of such holes 76 and five corresponding holes 78 has been found sufficient to permit the desired Vernier action. The holes 80 of plurality 72 thereof and the holes 82 of plurality 74 thereof respectively overlie the rows of perforations 42 and 46 and are each alignable with any of the perforations 44 and 48 respectively, just as the pluralities of holes 68 and 70 overlie rows of perforations 34 and 38 respectively and the holes 76 and 78 lare respectively alignable with any of the perforations 36 and 40. Three holes 72 spaced apart by e in. with three correspondingly and similarly spaced opposite holes 74 has been found sufficient to provide for adjustment of the chase 12 relative to the guide panel 10 by increments of in.

In Figs. l and 2, the pin assemblies 18 and 20 are shown for illustration as having their upstanding pm portions 84 land86 respectively extended through the centralmost of the corresponding holes 76 and 78.

Refeiring to Fig. 3, it will be seen that the pin assembly 18 (as is also the case with the pin assembly 20) lncludes a relatively thin, generally rectangular base portion 88 from which the upstanding pin element 84 (86 in the case of assembly 20) extends." Assemblies 18 and 20 are preferably formed of metal and the pin 84 may be connected with the base portion 88 in any suitable fashion, including integral joinder if desired.

'Ihe pins 84 and 86 are cylindrical and of umform diameter substantially equal to but very slightly less than the `diameter of each of the perforations 36, 40, 44, 48 and each of the holes 76, 78, 80 and 82, so that, when the pin 84 or `86 is extended through any of said perforations of the guide panel 10 and any of `said holes of the chase 12 aligned therewith and the pin 86 similarly extends through one of said perforations and one of said holes aligned therewith, the case 12 will be releasably but securely held relative to the guide panel 10. The pins 84 and 86 are thus of diameter adapted for relatively easy sliding movement through the mentioned perforations and holes, but of suflicient diameter to prevent any appreciable movement of the chase 12 relative to the guide panel 10 once the pins 84 and 86 are in operative position extending through a pair of aligned perforations and holes.

It will be clear that with the use of only the centermost holes 76 and 78, the pins 84 and 86 may be aligned with any of the perforations 36 and 40 respectively to provide for movement of the chase 12 relative to the guide panel 10 in increments of n. By shifting the pins 84 and 86 into the centermost of holes 72 and 74 and alignment thereof with diierent corresponding pairs f the perforations 44 and 48, the chase 12 may be moved relative to the guide panel 10 in intervals of 1/5 in. which, however, due to the offset of the perforations 44 and 48 from the perforations 36 and 40 represent incremental positions =of B4 in. relative to the guide panel 10. It will be apparent upon due consideration or trial that by utilizing a pair of holes 76 and 78 other than the centermost ones thereof, the chase 12 may be positioned relative to the guide panel 10 in increments of Vs in., while the use of the pins 84 and 86 with either outermost pair of holes 72 and 74 provides for positioning of the chase 12 at intervals of M6 in.

Thus, in the illustrative embodiment, the chase 12 may be moved and releasably secured relative to the guide panel 10 at any of a great plurality of positions measurable to r/a in. in the vertical direction without disturbing y the `alignment or orientation of the chase 12 relative .to the guide panel and the photo-sensitive plate 22 in a horizontal sense.

The image-forming tlm 16, which will normally be a negative transparency, although a positive could conceivably be used if desired, is secured by adhesive strips or the like 90 in covering relationship to a preferably rectangular opening 92 in the opaque sheet 14. Sheet 14 will normally comprise a piece of opaque, relatively heavy paper, such as is known in the trade as golden rod. The golden rod sheet 14 is in turn secured to the chase 12 by adhesive strips or the like 94 in such manner that the negative 16 overlies the aperture 66 of chase 12 and that portion of photo-sensitive surface 60 of plate 58 to receive the photo-impression of the negative 16. It will be understood that manual measurement and orientation of the golden rod sheet 14 or/ and the negative 16 relative to the chase 12 will be required where a separate sheet 14 is used, as in the currently preferred embodiment described for purposes of illustration. However, it is contemplated by the invention that, if desired, the negative 16 may be taped or otherwise directly secured to the chase 12 and the separate mounting sheet 14 omitted. In this case, the chase 12 itself may suitably be formed of golden rod.

Once the plate 58 is properly oriented on the guide panel 10 and the negative 16 is properly oriented and located on the chase 12, the remainder of the photosensitive surface 60 of plate 58 may be masked by any suit* able means such as opaque paper (not shown) with the chase 12 in some predetermined position relative to the plate 5S for making a first photo-impression, and a source of light (not shown) may then be shone through the negative 16 upon surface 66 to make the rst desired photo-impression. The pins 84 and 86 may then be withdrawn and the chase 12 relocated upon the guide panel 1t) for making a second desired photo-impression upon the plate 58 in vertically spaced relation to the first photoimpression. When the chase 12 has been relocated to the desired position, the pins 84 and 36 will be replaced through the appropriate aligned perforations and holes, it being observed that the mentioned perforations and holes themselves serve as a precise means of measurement during such relocation and that the orientation of the plate 58 and the negative 16 need not be changed or rechecked after initial positioning preparatory to making the rst impression.

It is to be understood that the particular use in terms of which the utility of the invention has been explained for purposes of illustration isnot to be deemed as all inclusive and that many other uses for the apparatus will occur to those skilled in the art. It will also be clear, however, that in the described use and in similar employments the apparatus is ideally adapted for accomplishing all of the above-mentioned and other objectives. Of particular note is the great saving of time and effort possible with the invention as compared with now conventional procedures wherein remeasurement and reorientation of the negative is required for each impression to be made when only a single negative is used. The elimination of such repeated measurements also eliminates one of the major causes of error which vfrequently results in the ex pensive wastage of time and materials.

Obviously, the invention possesses many advantages over the procedure of using a plurality of negatives each of which has to be separately produced and separately oriented relative to the work-piece to be processed.

Many minor changes and modifications could manifestly be made from the exact details of the structure disclosed for purposes of illustration without departing from the true spirit and intention of the invention. Accordingly, it is to be understood that the invention should be deemed limited only by the scope of the appended claims.

Having thus described the invention, what is claimed :as new and desired to be secured by Letters Patent is:

1. In photolithographic apparatus for processing a relatively thin, metallic plate having `a chemically treated, photosensitive surface by the successive imposition upon different, predeterminedly spaced areas of said surface of identical, photoimpressions of an image created by the passage of light through a single, image-forming negative, a guide panel having a pair of spaced, elongated series of perforations therethrough adjacent opposite extremities thereof and a llat face, each perforation of one series thereof having a respectively corresponding perforation in the other series thereof, each perforation being spaced from its corresponding perforation an equal, predetermined distance, said panel being adapted to receive said plate in superimposed relationship thereon with said surface remotely opposite said face, each of said series of perforations including Va rst straight row of equally spaced perforations, said first rows being parallel, each of said series of perforations including a second straight row of equally spaced perforations parallel to the rst row thereof, the perforations of said second rows thereof being offset from the perforations of the rst rows thereof longitudinally of the latter; a frame-like chase having a pair of spaced holes therethrough and a central aperture therethrough, said chase being removably superirnposable relative to said face of the panel with said plate therebetween and a portion of said surface exposed through said aperture, said chase being adapted for carrying said negative in disposition aligned with said aperture, said pair of holes being spaced the same said predetermined distance as each perforation is spaced from its corresponding perforation, said holes being alignable with any of a number of the perforations of said one series thereof and its corresponding perforation in the other series thereof, said chase being provided with a second pair of holes spaced apart the same distance as said second rows of perforations, said second pair of holes being alignable with any perforation of one of said second rows thereof and a corresponding perforation of the other of said second rows thereof; and pin means for each hol-e respectively each removably received Within its hole and a perforation aligned therewith for releasably holding the chase in any of a number of predetermined positions relative to the panel and the plate, said pin means each being removably receivable within a hole of said second pair thereof and a perforation aligned therewith.

2. In photolithographic apparatus for processing a rela tively thin, metallic plate having a chemically treated, photosensitive surface by the successive imposition upon different, predeterminedly spaced areas of said surface of identical, photoimpressions of an image created by the passage of light through a single, image-forming negative, a guide panel having a pair of spaced, elongated series of perforations therethrough adjacent opposite extremities thereof and a at face, each perforation of one series thereof having a respectively corresponding perforation in the other series thereof, each perforation being spaced from its corresponding perforation an equal, predetermined distance, said panel being adapted to receive said plate in superimposed relationship thereon with said surface remotely opposite said face, each of said series of perforations including a rst `straight row of equally spaced perforations, said first rows being parallel, each of said series of perforations including a second straight row of equally spaced perforations parallel to the rst row thereof, the perforations of said second rows thereof being offset from the perforations of the rst rows thereof longitudinally of the latter; a frame-like chase having a pair of spaced holes therethrough and a central aperture therethrough, said chase being removably superimposable relative to said face of the panel with said plate therebetween and a portion of said surface exposed through said aperture, said chase being adapted for carrying said negative in disposition aligned with said aperture, said pair 7 of holes being spaced the same said predetermined distance aseach perforation isl spaced from its corresponding perforation, said holes being alignable with any of a number of the perforations of said one series thereof and its corresponding perforation in the other series thereof,`

cach of said holes comprising one of'a plurality thereof, saidvholes of each plurality thereof being equally spaced and arranged in a straight line, said lines of holes being parallel, the spacing between holes of each plurality thereof being diierent from the spacing between the perforations of each row thereof; and pin means for each asentar# hole respectively each removably received within its hole and a perforation aligned therewith for releasably holding' the chase in any of a number of predetermined positions relative to the panel and the plate, said pin means each being'removably receivable within any`of said holes and a perforation aligned therewith.

Hunter Nov. 16, 1937 Kessler June 21, 1955 

